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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Kinetic Inductance Traveling Wave Amplifier Designs for Practical Microwave Readout Applications

Abstract A Kinetic Inductance Traveling Wave Amplifier (KIT) utilizes the nonlinear kinetic inductance of superconducting films, particularly niobium titanium nitride (NbTiN), for parametric amplification. These amplifiers achieve remarkable performance in terms of gain, bandwidth, and compression power and frequently approach the quantum limit for noise. However, most KIT demonstrations have been isolated from practical device readout systems. Using a KIT as the first amplifier in the readout chain of an unoptimized microwave SQUID multiplexer coupled to a transition-edge sensor microcalorimeter, we see an initial improvement in the flux noise [1]. One challenge in KIT integration is the considerable microwave pump power required to drive the non-linearity. To address this, we have initiated efforts to reduce the pump power by using thinner NbTiN films and an inverted microstrip transmission line design. In this article, we present the new transmission line design, fabrication procedure, and initial device characterization—including gain and added noise. These devices exhibit over 10 dB of gain with a 3 dB bandwidth of approximately 5.5–7.25 GHz, a maximum practical gain of 12 dB, and typical gain ripple under 4 dB peak to peak. We observe an appreciable impedance mismatch in the NbTiN transmission line, which is likely the source of the majority of the gain ripple. Finally, we perform an initial noise characterization and demonstrate system-added noise of three quanta or less over nearly the entire 3 dB bandwidth.

Physics↗
DOE OSTI2026

Cryogenic-Refined MOSFET Modeling for Oscillator, Frequency Divider, and Amplifier Designs Below 4 K

Capturing device characteristic changes at cryogenic temperatures is crucial for cryo-CMOS circuit designs. In this work, we present an isothermal cryogenic-refined modeling approach for CMOS transistors that is simple, low overhead, and easy to implement while offering the required accuracy for predicting circuit performance at the designated temperatures. Guided by die-level measurement data and circuit design principles, the model introduces corrections to only five critical parameters: threshold voltage, carrier mobility, elevated low-frequency flicker noise, dominant high-frequency shot noise, and subthreshold swing (SS). These refinements are implemented around the foundry-provided SPICE model, which is typically validated only down to about 200 K. With these adjustments, the proposed cryogenic-refined model achieves less than 5% error in both large-signal metrics (I–V characteristics) and small-signal parameters (e.g., transconductance) when compared with device measurements at deep-cryogenic temperatures. The methodology is validated in two advanced technologies: TSMC 40-nm CMOS and GlobalFoundries (GF) 45-nm RF-SOI. We further demonstrate its applicability in three representative RF circuits: a 30-GHz LC oscillator, a high-speed current-mode-logic (CML) frequency divider (FD), and a subthreshold Gb/s amplifier, all showing close agreement between simulated predictions and measurements performed at 4 and 2.5 K. Finally, we believe that the proposed approach is implementation-friendly and can significantly accelerate the development of cryo-CMOS integrated circuits.

circuit modeling↗
DOE OSTI2021

Temporal prepulse contrast degradation in high-intensity CPA lasers from anisotropy of amplifier gain media

Here, we present a study of the temporal pre-pulse contrast degradation of high focused intensity pulses produced in CPA laser systems due to imperfections in amplifier design, alignment of amplifier components, and crystal inhomogeneity. Using an extended cross-polarized imaging technique, we demonstrate the presence of multiple crystal domains inside Ti:sapphire slabs with ≈10 cm diameter. Furthermore, the results of our numerical calculations show that crystalline c-axis orientation inhomogeneity caused by these crystal domains can lead to generation of pre-pulses with relative contrast >10 -10 within several picoseconds before the main pulse. In a multiple-slab amplifier head configuration sometimes used in high repetition rate systems, the misalignment of the amplifier slabs crystalline c-axes with respect to each other can lead to the generation of pre-pulses with relative contrast as high as 10 -6 , depending on the magnitude of misalignment.

47 OTHER INSTRUMENTATION↗
DOE OSTI2017

Low-Noise Amplifiers and Superconducting Flex Circuits for Frequency Domain Multiplexed Readout of Detector Arrays

The next-generation ground-based cosmic microwave background (CMB) experimental program aims to provide definitive measurements of the early universe using telescopes configured with large focal plane arrays requiring ~100,000 detectors and associated readout amplifiers and interconnecting components that are currently unavailable commercially. We describe research to demonstrate the feasibility of developing low-noise cryogenic amplifiers based on series SQUID arrays that are suitable for frequency domain multiplexed readout of large numbers of CMB detectors, and the feasibility of developing robust superconducting flex cables that will simplify cryogenic systems integration for large CMB instruments. Two iterations of prototype series SQUID array amplifier designs were completed. The designs were optimized using modeling and simulation tools to meet the requirements for CMB detector readouts. Two fabrication runs were completed, and a large number of devices from each design iteration were tested and characterized at 4 K. We also completed the development of processes for the fabrication of prototype superconducting flex cables on 4" wafers. Samples were tested for strength and robustness, and to determine the critical current at 4 K as a function of trace width. The new generation of series SQUID array amplifier designs exhibit excellent performance characteristics – very smooth output characteristics that simplify tuning and operation, low input inductance, low current noise referred to the input, and low power dissipation that for the first time will enable these devices to be operated at the focal plane array stage of CMB instruments. The processes developed in Phase I to produce superconducting flex cables were used to complete the fabrication of a full wafer with several test and sample flex circuits. The 6-micron thick flex material is very strong with a breaking strength of several pounds for a 20-mm wide strip. Critical current density was reasonable and scaled with trace width as expected.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2024

PHIL Interface Design for Use With a Voltage-Regulated Amplifier

Power hardware-in-the-loop (PHIL) has emerged as a leading strategy to thoroughly assess the impact of proprietary inverter controls on a specific power system. The development of a PHIL test bed typically involves an inverter under test, a power amplifier, controllable DC supply, and a digital real-time simulator (DRTS) to simulate the power system under study. As a result of PHIL nonidealities, a form of digital compensation within the DRTS is used, which is commonly referred to as a PHIL interface. Many existing methods use legacy power amplifiers that do not contain internal voltage regulation. These existing interface methods are based around a voltage regulator within the DRTS and do not consider the interaction with the controls in newer amplifiers. In this study, a three-step approach of PHIL interface development for modern power amplifiers with built-in voltage regulation is introduced and is validated in hardware with a 30-kW grid-following inverter.

DRTS↗
DOE OSTI2026

Design of an optical amplifier for amplified OSC in IOTA facility at Fermilab

Optical stochastic cooling (OSC) is a cutting-edge beam cooling technology to reduce, control the 3 dimensional spread and the motion of particle beams. It has recently been successfully, experimentally, demonstrated in Fermilab's IOTA storage ring, marking a major step forward in beam cooling. OSC has the potential to significantly improve both the performance and flexibility as a beam cooling system. One promising way to boost OSC performance is by adding a high-gain optical amplifier. However, this amplifier must be carefully designed to meet the specific constraints of the OSC system. A major challenge lies in the limited optical delay, which is just 6 mm for the case of IOTA, set by the beam bypass, restricts us to use a short-length gain medium. This, along with IOTA’s high repetition rate and the relatively long duration of the optical pulses, limits the peak power available for the pump laser without damaging the crystal, which is crucial for achieving strong nonlinear gain. Additionally, it's essential to preserve the phase coherence of the undulator radiation during amplification, which further complicates the amplifier design. This report details a specialized amplifier setup that addresses these challenges, includes simulations of the integrated system, and summarizes the latest experimental progress and results.

Mondal, Abhishek [Fermilab]↗
DOE OSTI2017

Broadband parametric amplifiers based on nonlinear kinetic inductance artificial transmission lines

Here, we present broadband parametric amplifiers based on the kinetic inductance of superconducting NbTiN thin films in an artificial (lumped-element) transmission line architecture. We demonstrate two amplifier designs implementing different phase matching techniques: periodic impedance loading and resonator phase shifters placed periodically along the transmission line. Our design offers several advantages over previous CPW-based amplifiers, including intrinsic 50 Ω characteristic impedance, natural suppression of higher pump harmonics, lower required pump power, and shorter total trace length. Experimental realizations of both versions of the amplifiers are demonstrated. In conclusion, with a transmission line length of 20 cm, we have achieved gains of 15 dB over several GHz of bandwidth.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2015

Development FD-SOI MOSFET Amplifiers for Integrated Read-Out Circuit of Superconducting-Tunnel-Junction Single-Photon-Detectors

We proposed a new high-resolution single-photon infrared spectrometer for search for radiative decay of cosmic neutrino background (CνB). The superconducting-tunnel-junctions(STJs) are used as a single-photon counting device. Each STJ consists of Nb/Al/Al x O y /Al/Nb layers, and their thicknesses are optimized for the operation temperature at 370 mK cooled by a 3 He sorption refrigerator. Our STJs achieved the leak current 250 pA, and the measured data implies that a smaller area STJ fulfills our requirement. FD-SOI MOSFETs are employed to amplify the STJ signal current in order to increase signal-to-noise ratio (S/N). FD-SOI MOSFETs can be operated at cryogenic temperature of 370 mK, which reduces the noise of the signal amplification system. FD-SOI MOSFET characteristics are measured at cryogenic temperature. The Id-Vgs curve shows a sharper turn on with a higher threshold voltage and the Id-Vds curve shows a nonlinear shape in linear region at cryogenic temperature. Taking into account these effects, FD-SOI MOSFETs are available for read-out circuit of STJ detectors. The bias voltage for STJ detectors is 0.4 mV, and it must be well stabilized to deliver high performance. We proposed an FD-SOI MOSFET-based charge integrated amplifier design as a read-out circuit of STJ detectors. The requirements for an operational amplifier used in the amplifier is estimated using SPICE simulation. The op-amp is required to have a fast response (GBW ≥ 100 MHz), and it must have low power dissipation as compared to the cooling power of refrigerator.

47 OTHER INSTRUMENTATION↗
DOE OSTI2021

Characterization and QC practice of 16-channel ADC ASIC at cryogenic temperature for Liquid Argon TPC front-end readout electronics system in DUNE experiment

ColdADC is a low-noise 16-channel analog-to-digital converter ASIC designed for cold readout electronics of Liquid Argon Time Projection Chambers (LArTPCs) in the Deep Underground Neutrino Experiment (DUNE). ColdADC was specifically designed for operation at cryogenic temperatures (77 K–89 K). Cold electronics is considered to be an enabling technology for liquid argon detectors in neutrino experiments. The main function of the chip is to digitize signals from the 16-channel charge-sensitive amplifier designed at BNL (LArASIC) and send digitized signals to the data aggregator and serializer chip (COLDATA). ColdADC operates with a resolution of 12 bits and a sampling rate of 2 MS/s per channel. A complete characterization of prototype chips was conducted at cryogenic temperature, involving power consumption, noise and linearity performance. In the first DUNE Far-Detector module, 384000 data channels will be read out, corresponding to 24000 ColdADC chips. Therefore, systematic testing of ColdADC chips at cryogenic temperature is vital for the quality and reliability of DUNE Single-Phase modules. We have developed a Quality Control (QC) test stand that includes ColdADC evaluation and characterization at cryogenic temperature. The QC procedure was applied to a first batch of 33 chips, corresponding to 528 data channels. The obtained results meet all the required DUNE specifications for ColdADC. Moreover, the testing outcome allowed us to identify possibilities of performance optimization that are currently being addressed in the design of the next version of the chip. The Quality Control procedure is proved to be successful and will be a reference design for future large-batch production testing of final ColdADC ASICs.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

Focal Plane Array Low Background Testing (Focal Plane Array Characterization under a Low Background)

Most infra-red (IR) imagers for tactical applications use a direct injection (DI) input amplifier design. Fewer transistors in the unit cell allow the read-out electronic circuit (ROIC) to be minimized. This allows either more room for charge integration capacitors or finer pixel pitches. These ROICs work well at high background irradiance levels. However, at low background irradiance levels photocurrent inject efficiency for a DI unit cell amplifier is reduced. Some models have shown that this efficiency can drastically affect performance under low background conditions. The main benefit for Sandia National Laboratories (SNL) and L-3 Communications Cincinnati Electronics (L-3) was a better understanding of these types of sensors under low background conditions. It also provided the opportunity for an independent analysis of these sensors. The purpose of this project was to measure DI for low light levels under different operating temperatures of the L-3 CE103 a 1280 x 1024 indium antimonide 15 micron pitch detector. Results showed DI efficiency approaches 75% under extremely low light levels. Additionally, measured data didn't conform well to traditional circuit based models indicated that other effects are contributing to DI efficiency. A "spot scanning" PSF measurement was also conducted to measure pixel-to-pixel crosstalk for this array. Spot scanning data showed near ideal performance.

47 OTHER INSTRUMENTATION↗
DOE OSTI2014

Nondegenerate parametric generation of 2.2-mJ, few-cycle 2.05-μm pulses using a mixed phase matching scheme

We describe the production of 2.2-mJ, ∼6 optical-cycle-long mid-infrared laser pulses with a carrier wavelength of 2.05 μm in a two-stage β-BaB{sub 2}O{sub 4} nondegenerate optical parametric amplifier design with a mixed phase matching scheme, which is pumped by a standard Ti:sapphire chirped-pulse amplification system. It is demonstrated that relatively high pulse energies, short pulse durations, high stability, and excellent beam profiles can be obtained using this simple approach, even without the use of optical parametric chirped-pulse amplification.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2014

Strong environmental coupling in a Josephson parametric amplifier

We present a lumped-element Josephson parametric amplifier designed to operate with strong coupling to the environment. In this regime, we observe broadband frequency dependent amplification with multi-peaked gain profiles. We account for this behavior using the “pumpistor” model which allows for frequency dependent variation of the external impedance. Using this understanding, we demonstrate control over the complexity of gain profiles through added variation in the environment impedance at a given frequency. With strong coupling to a suitable external impedance, we observe a significant increase in dynamic range, and large amplification bandwidth up to 700 MHz giving near quantum-limited performance.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2026

Accessing terapascal pressures on two-stage light-gas guns for high-energy-density research

We present pressure amplifiers that have been developed to enable the study of material behavior at terapascal (TPa) pressures using two-stage light-gas gun (2SLGG) facilities. When impacted by a hyper-velocity projectile, Mach reflections within the pressure amplifier eventually merge to form a Mach stem, generating a planar output shock that greatly exceeds the initial drive. Validation experiments demonstrated that peak pressures of 0.6 and 1.073 TPa were achieved in quartz samples for two different amplifier designs. These pressures represent an approximately fivefold increase over the sample pressures typically attainable at 2SLGG facilities. The temporal and spatial uniformity of the pressure drive is suitable for high-precision equation-of-state measurements of materials relative to a shock standard. This work greatly extends the capabilities of 2SLGG facilities and opens new avenues of study in high-energy-density physics using these drivers.

Gorman, Martin G. [First Light Fusion, Oxford (Uni↗
DOE OSTI2018

Test beam measurement of ams H35 HV-CMOS capacitively coupled pixel sensor prototypes with high-resistivity substrate

In the context of the studies of the ATLAS High Luminosity LHC programme, radiation tolerant pixel detectors in CMOS technologies are investigated. To evaluate the effects of substrate resistivity on CMOS sensor performance, the H35DEMO demonstrator, containing different diode and amplifier designs, was produced in ams H35 HV-CMOS technology using four different substrate resistivities spanning from 80 cm to 1000 cm. A glueing process using a high-precision flip-chip machine was developed in order to capacitively couple the sensors to FE-I4 Readout ASIC using a thin layer of epoxy glue with good uniformity over a large surface. The resulting assemblies were measured in beam test at the Fermilab Test Beam Facilities with 120 GeV protons and CERN SPS H8 beamline using 180 GeV pions. Furthermore, the in-time efficiency and tracking properties measured for the different sensor types are shown to be compatible with the ATLAS ITk requirements for its pixel sensors.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Performance of Hamamatsu VUV4 SiPMs for detecting liquid argon scintillation

Detection of light signals is crucial to a wide range of particle detectors. In particular, efficient detection of vacuum ultraviolet (VUV) light will provide new opportunities for some novel detectors currently being developed, but is technically challenging. In this paper, we characterized the performance of Hamamatsu VUV4 silicon photomultipliers (SiPMs) for detecting VUV argon scintillation light without wavelength shifting. Using a customized cryogenic amplifier design, we operated two models of VUV4 SiPMs inside liquid argon and thoroughly examined their direct sensitivities to liquid argon scintillation. In addition to describing their cryogenic performance, we measured a photon detection efficiency of 14.7 +1.1 -2.4 % and 17.2 +1.6 -3.0 % at 128 nm for these two VUV4 models for operation at 4 V of overvoltage, with the main uncertainty arising from the SiPM reflectivity for VUV light.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2022

Impact of the optical parametric amplification phase on laser pulse compression

Optical parametric chirped-pulse amplification (OPCPA) is an effective way to generate ultrashort pulses that has been used extensively for a variety of applications requiring high peak intensities. Precise control and measurement of a system’s spectral and spatial phases are required for Fourier transform–limited pulse compression and diffraction-limited focusing. Phase accumulated during optical parametric amplification (OPA) can degrade the compressibility and focusability of the pulse, reducing peak intensity. We used analytic and numerical analysis of OPA to study the influence of crystal parameters, wavefront of the pump and signal, and their relative optical alignment on the accumulated phase. Here, we show that the accumulated signal phase is largely independent of amplifier saturation and, with significant local wavefront gradients in the signal or pump beam, the quality of the compressed pulses can be degraded. We use first-order expressions for the pump- and signal-angle sensitivity to evaluate an OPCPA system consisting of a highly deuterated potassium dihydrogen phosphate (DKDP) amplifier designed to support bandwidth for 15 fs pulses centered at 920 nm.

47 OTHER INSTRUMENTATION↗
DOE OSTI2022

Characterization of Hamamatsu VUV4 SiPM Performance for Liquid Argon Scintillation

Detection of light signals is crucial to a wide range of particle detectors. In particular, efficient detection of vacuum ultraviolet (VUV) light will provide new opportunities for some novel detectors currently being developed, but is technically challenging. In this article, we characterized the performance of Hamamatsu VUV4 silicon photomultipliers (SiPMs) for detecting VUV argon scintillation light without wavelength shifting. Here, using a customized cryogenic amplifier design, we operated two models of VUV4 SiPMs inside liquid argon and thoroughly examined their direct sensitivities to liquid argon scintillation. In addition to describing their cryogenic performance, we measured a photon detection efficiency of 14.7+1.1–2.4% and 17.2+1.6–3.0% at 128 nm for these two VUV4 models for operation at 4 V of overvoltage, with the main uncertainty arising from the SiPM reflectivity for VUV light.

Pershing, Teal↗